Negative-working photoresist composition

Abstract

Disclosed is a novel negative-working chemical-amplification photoresist composition comprising (A) an alkali-soluble resin, (B) an acid-generating agent and (C) a crosslinking agent, of which the component (B) is an onium salt compound having a specific fluoroalkyl sulfonate ion as the anionic moiety and the component (C) is a specific ethyleneurea compound substituted for at least one nitrogen atom by a hydroxymethyl or alkoxymethyl group. The photoresist composition is particularly suitable for the formation of a photoresist layer on a substrate surface provided with an undercoating of a water-insoluble organic anti-reflection film exhibiting excellent pattern resolution and orthogonal cross sectional profile of the patterned resist layer with a good temperature latitude in the post-exposure baking treatment for latent image formation.

What is claimed is:  
     
       1. A negative-working photoresist composition which comprises, as a uniform solution in an organic solvent: 
       (A) 100 parts by weight of an alkali-soluble resin;  
       (B) from 0.5 to 20 parts by weight of an onium salt compound of which the anionic moiety is a fluoroalkyl sulfonate anion as a radiation-sensitive acid-generating agent;  
       (C) from 3 to 50 parts by weight of an ethyleneurea compound represented by the general formula                    
        in which R 1  and R 2  are each a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms and R 3  and R 4  are each a hydrogen atom, a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, as a crosslinking agent; and  
       (E) from 0.01 to 1.0 part by weight, per 100 parts by weight of the component (A), of a phosphorous-containing oxoacid.  
     
     
       2. The negative-working photoresist composition as claimed in  claim 1  in which the fluoroalkyl sulfonate anion in the component (B) is a perfluoroalkyl sulfonate anion having 1 to 10 carbon atoms. 
     
     
       3. The negative-working photoresist composition as claimed in  claim 1  in which the alkali-soluble resin as the component (A) is a copolymer of hydroxystyrene and styrene consisting of from 60 to 97% by moles of hydroxystyrene units and from 40 to 3% by moles of styrene units, a copolymer of hydroxystyrene and styrene consisting of from 60 to 97% by moles of hydroxy-styrene units and from 40 to 3% by moles of styrene units substituted by alkali-insoluble groups for from 5 to 30% of the hydroxyl groups or a polyhydroxystyrene substituted by alkali-insoluble groups for from 3 to 40% of the hydroxyl groups. 
     
     
       4. The negative-working photoresist composition as claimed in  claim 3  in which the alkali-insoluble group is selected from the group consisting of tertiary alkoxycarbonyl groups and alkyl groups having 1 to 4 carbon atoms. 
     
     
       5. The negative-working photoresist composition as claimed in  claim 1  in which at least one of the groups denoted by R 1  and R 2  is an alkoxy group having 1 to 4 carbon atoms, the rest, if any, being a hydroxyl group, and the groups denoted by R 3  and R 4  are each a hydrogen atom. 
     
     
       6. The negative-working photoresist composition as claimed in  claim 1  which further comprises: (D) from 0.01 to 1.0 part by weight of an aliphatic amine compound per 100 parts by weight of the component (A). 
     
     
       7. The negative-working photoresist composition as claimed in  claim 6  in which the aliphatic amine compound is selected from the group consisting of trialkyl amine compounds, dialkyl amine compounds, trialkanol amine compounds and dialkanol amine compounds, of which the alkyl group or alkanol group has 1 to 5 carbon atoms.